Apparently, most biologically active isomer of conjugated linoleic acid (CLA) is cis-9, trans-11, which is accounted for more than 80% of the isomers of CLA in ...
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Asian-Aust. J. Anim. Sci. Vol. 22, No. 1 : 49 - 56 January 2009 www.ajas.info
Effects of Protected Conjugated Linoleic Acid Supplementation on Milk Fatty Acid in Dairy Cows N. Piamphon, C. Wachirapakorn1, *, M. Wanapat1 and C. Navanukraw1 Faculty of Agro-industrial Technology, Rajamangala University of Technology Isan Kalasin campus, Kalasin, 46000, Thailand ABSTRACT : The objective was to determine the effects of supplementation of protected conjugated linoleic acid (CLA), CLA-20 comprising 10% each of cis-9, trans-11 and trans-10, cis-12, on milk production and fatty acid profiles in plasma and milk in lactating dairy cows. Five mid-lactation, multiparous crossbred Holstein Friesian cows with average 402±20 kg BW were used in a 5×5 Latin square design for 21-d periods. Cows were given a total mixed ration (TMR) and supplemented with CLA-20 at 0, 20, 40, 80 and 160 g/d. The results showed that dry matter intake depression occurred in cows supplemented with CLA-20 at 160 g/d. Milk production slightly increased when CLA-20 supplementation was at 20, 40 and 80 g/d. However, 3.5% fat-corrected milk (FCM) was not affected by CLA-20 supplementation. Increased levels of CLA-20 supplementation resulted in a significantly decreased percentage of milk fat. Plasma concentrations of fatty acid were not altered by the amounts of CLA-20 supplementation except for the concentration of trans10, cis-12 CLA. For all dietary treatments, percentages of fatty acids (C4:0, C6:0, C8:0, C13:0, C14:0 C14:1 C15:0 C15:1 C16:0, C16:1, C18:1n9t, C18:2n6t, C18:2n6c, C20:0, C18:3n6, C18:3n3, C20:1 and C20:3n6) in milk fat were similar. Concentrations of C10:0, C11:0, C12:0 and C18:1n9c were decreased cubically and C18:0 was elevated linearly (p
